LONDON — Back in her comfort zone on Centre Court, Serena Williams delivered an overpowering statement: When her serve is steaming, she’s the woman to beat at Wimbledon.

Putting aside her recent comments that led to a couple of apologies and a brief spat with Maria Sharapova, Williams looked every bit the five-time champion. She began her Wimbledon title defense with a 6-1, 6-3 victory over Mandy Minella of Luxembourg.

“For me, it’s the greatest moment for a tennis player, to walk out on Centre Court,” Williams said after her first match at Wimbledon since winning the Olympic gold medal there last year. “That was such a great moment, too. So many great memories on this court.”

Top-ranked Novak Djokovic also opened with a straight-sets victory, beating Florian Mayer of Germany 6-3, 7-5, 6-4. Mayer is a two-time Wimbledon quarterfinalist, losing to Djokovic at that stage last year. But he was never in danger of springing another stunner following Rafael Nadal’s first-round exit a day earlier.

Djokovic took a 3-0 lead in the first set and broke for a 6-5 lead in the second to take control. He served out the match to love before saluting the crowd with a fist pump.

“It was a big pleasure again performing here on Centre Court in front of the packed crowd,” Djokovic said. “For the first round, it was tricky. ... I think (Mayer’s) game is really well suited for grass, so it took a lot of effort.”

For Williams, this was a chance to put the focus back on tennis following the verbal jousting with Sharapova over their private lives — and comments about an Ohio rape case for which she had to apologize — and she took full advantage.

As usual on grass, the top-ranked Williams dominated with her hard serve, winning the first set without dropping a point on her service game. Her main weapon let her down only at the start of the second set, when Minella took a 2-0 lead after Williams double-faulted on break point.

She was one point from going down 3-0 but then won 15 of the next 18 points to take a 4-2 lead, and broke again to wrap up the victory.

“I feel like I was a little rusty for some reason today,” Williams said. “I don’t feel like I played my best. I felt really upset when I lost my serve in the second set. With that being said, I think Mandy played really well.”

Much of the pre-tournament talk was about Williams and Sharapova, the two top players in the game who are on opposite sides of the draw and can’t meet before the final.

“It hasn’t been a distraction. Like I said, I’m just here to focus on the tennis,” Williams said. “I’m just here to play Wimbledon. It’s the premier tournament in the world, of the year, so that’s what’s most important. ... We’re playing on opposite days, so we don’t really see each other.”

Williams improved her career record to 68-8 at the All England Club and extended her career-best winning streak to 32 matches, which included her second French Open title.

“I don’t think about it,” Williams said, referring to her streak. “Every single time I step out on the court it’s a new match.”

Kimiko Date-Krumm, the 42-year-old Japanese veteran, had an even easier time getting past an opponent. She needed just 44 minutes to complete a romp over Carina Witthoeft, an 18-year-old German less than half her age and making her Grand Slam debut.

Date-Krumm is the second-oldest player to win a match at Wimbledon after Martina Navratilova, who was 47 when she reached the second round in 2004.

Sixth-seeded Li Na of China also cruised into the second round, beating Michaella Krajicek of the Netherlands 6-1, 6-1.

Nadal, a two-time Wimbledon champion, was knocked out in straight sets by 135th-ranked Steve Darcis of Belgium on Monday — the Spaniard’s first loss in the opening round of any Grand Slam event.

The only top player Tuesday who had any difficulty advancing was French Open runner-up David Ferrer. He overcame a second-set slump and a scary late fall to beat Martin Alund of Argentina 6-1, 4-6, 7-5, 6-2.

Coming off his first Grand Slam final, the fourth-seeded Spaniard looked as if he could follow Nadal out of the tournament. Alund won the second set and pushed hard in the third. But Ferrer broke for a 6-5 lead and then went 5-1 up in the fourth. At 3-1, however, he fell and grimaced in pain after his left foot slid backward on the grass. Ferrer got back up, and went on to break Alund again. He served out the match with an ace, and afterward said his foot was “fine.”

Most other matches went according to plan.

No. 8 Juan Martin Del Potro made a winning return to Grand Slam competition, defeating Albert Ramos of Spain 6-2, 7-5, 6-1 after sitting out the French Open because of respiratory problems. No. 12 Kei Nishikori of Japan and No. 13 Tommy Haas of Germany won in straight sets, but No. 16 Philipp Kohlschreiber of Germany wasted a two-set lead against Ivan Dodig of Croatia and then had to retire in the fifth, citing the flu.